1. Field of the Invention
The present invention relates to an image printing apparatus, and more particularly, to an image printing apparatus and a control method thereof capable of outputting an optimum image adjusted in accordance with characteristics of the printing material by reading the characteristics of the printing material, and by resetting functional set values for respective components of the image printing apparatus, and by performing the printing operation accordingly.
2. Description of the Related Art
Generally, an image printing apparatus such as a printer, etc. forms characters or images on printing material in accordance with image data signals conveyed from an external device such as a computer, etc. Such an image printing apparatus includes a photosensitive section for forming latent electrostatic images, a charging section for charging the photosensitive section, an exposing section for forming latent electrostatic images of a certain pattern by projecting a beam on and selectively eliminating electric charges on the charged photosensitive section, a developing section for developing the latent electrostatic image by applying developer on the latent electrostatic image, a transferring/fixing section for transferring the developed image by pressing and heating processes, a printing material feeding section for sequentially feeding the printing material to the transferring/fixing section, and a controlling section for controlling the above-mentioned sections.
One example of a wet type electrophotographic image printing apparatus includes a photosensitive belt as the photosensitive section, which is wrapped around rollers disposed within a body frame and which rotatably travels a certain path. Around the photosensitive belt, an antistatic electrostatic unit, a charging unit, an exposing unit, a developing unit, a drying unit, and a transferring/fixing unit are installed.
Further, the wet type electrophotographic image printing apparatus includes a developing fluid supplying unit for constantly supplying the developing fluid of a certain density to the developing unit, a printing material feeding unit for sequentially feeding the printing material to the transferring/fixing unit, and a controlling section for controlling the respective units described above.
The electrostatic unit completely eliminates any electric charge left on the photosensitive belt, and the charging unit newly charges the photosensitive belt. The exposing unit forms a latent electrostatic image on the photosensitive belt by selectively eliminating electric charge of the area where the image is formed on the charged photosensitive belt in accordance with the pattern of the image. The exposing unit includes a plurality of laser projecting devices corresponding to a plurality of colors such as yellow, magenta, cyan, and black, or the like for projecting laser beams toward the photosensitive belt.
The developing unit forms a visual image by projecting the developing fluid composed of a toner in a solid state and a carrier in a liquid state, and thus attaching the toner on the latent electrostatic image on the surface of the photosensitive belt. The developing unit includes four developing devices corresponding to the respective colors. Each developing device includes a pair of developing rollers and a pair of squeezing rollers. Here, the pair of squeezing rollers eliminate the carrier in the developing fluid by squeezing out the carrier from the developing fluid.
The drying unit eliminates the residue of carrier which is still left after the developing unit is to an extent that allows image transferring at the transferring/fixing unit. The drying unit includes a drying roller, and a pair of regeneration rollers which are selectively rotated in tight contact with the drying roller. Further, the transferring/fixing unit transfers the image developed on the photosensitive belt to the printing material fed by the printing material feeding unit, and includes a transferring roller and a fixing roller.
The printing material feeding unit includes a feeding cassette for receiving and storing the printing materials, a printing material feeding path extending from the feeding cassette to the transferring/fixing unit, a pickup roller for picking up one of the printing materials stored in the feeding cassette and for putting the printing material on the printing material feeding path, a plurality of feeding rollers for feeding the printing material entered in the printing material feeding path, an aligning roller for aligning the printing material fed by the feeding roller on the front end of the transferring/fixing unit, printing material delay sensing sensors for sensing the delay of the printing material feeding, and a driving section for driving the respective rollers.
The controlling section controls the above-mentioned units in accordance with a certain program, while determining whether the feeding of printing material is delayed or not by the sensed results inputted from the printing material delay sensing sensors. The controlling section stops the printing operation and indicates a jam error, when there is a delay in printing material feeding.
In a conventional wet type electrophotographic image printing apparatus, when a printing command is applied, the electrostatic unit is operated to eliminate the residual electric charge of the photosensitive belt, and the charging unit sequentially charges the surface of the photosensitive belt with a certain electric potential (approximately of 500-700V).
After that, the exposing unit forms a latent electrostatic image by projecting a laser beam which is converted in accordance with the electric data of the to-be printed area of the charged photosensitive belt, and the latent electrostatic image is developed as the same passes through the developing unit.
Through the above processes, the image developed on the photosensitive belt by the toner, is transferred to the transferring roller as the image passes through the transferring/fixing unit. The image transferred to the transferring roller is transferred to the printing material passing between the transferring and fixing rollers, and the image is completely attached to the printing material by the heat and pressure from the fixing roller.
Here, one of the printing materials is picked up by the pickup roller from the feeding cassette, and is fed to the aligning roller by the plurality of feeding rollers, and is stopped at the aligning roller. Then as the photosensitive belt is rotated a distance corresponding to the distance from the contact point of the transferring and fixing rollers to the aligning roller, thus the image on the photosensitive belt reaches the contact point of the transferring and fixing rollers, the aligning roller is rotated, and the printing material is fed between the transferring and fixing rollers. The printing material, which is printed with the image while passing between the transferring and fixing rollers, is stored in a distributing tray, finally.
As described above, printing is basically the process in which the developer, i.e., the toner is attached to the printing material. In view of this, it is apparent that the printing quality seriously depends on the various characteristics of the printing material, such as thickness, surface roughness, glossiness, material type, conductivity, etc., and the maintenance status of the printing material, in particular, whether the term of use of the printing material has expired or not (that is, if the expiration date has passed), etc. Accordingly, it is necessary to adjust functional set values for the respective components of the image printing apparatus in accordance with the characteristics of the printing material, such as the voltage for charging unit, level of laser beam for the exposing unit, the voltage for the developing unit, developing fluid density, and temperature for fixing process, etc.
The conventional image printing apparatus, however, has fixed functional set values for the respective parts of the image printing apparatus, so that precise values of the parameters for the respective printing material can not be guaranteed, and accordingly, the optimum image adjusted in accordance with the individual characteristics of the printing material can not be guaranteed.
Meanwhile, some of the conventional image printing apparatuses enable a user to directly or indirectly input functional set values for the respective parts of the image printing apparatus. Such an image printing apparatus, however, has a shortcoming in that the manual inputting process is bothersome for the user, and the user can not print an optimum image when the user does not know the exact characteristics of the printing material (such as when using a sheet of printing material whose characteristics are not indicated) since the user can not set the exact functional set values for the printing material.
It is therefore an object of the invention to provide an improved printing apparatus and method.
A further object of the invention is to provide a printing apparatus and method which automatically adjusts the printing based on the characteristics of the printing material.
A yet further object of the invention is to provide a printer which can discriminate between different types of printing materials.
A still further object of the invention is to provide a printer which can discriminate between different brands of printing materials.
A still yet further object is to provide a printer which can discriminate printing materials which have passed their expiration date.
Another object of the invention is to provide a printer which can avoid damage to the printer from inappropriate printing materials.
The present invention has been developed to overcome the above-mentioned problems of the prior art and to achieve the above objects by providing an image printing apparatus and a control method thereof capable of outputting an optimum image by reading the characteristic data of the printing material, and automatically resetting the functional set values for the respective functional parts of the image printing apparatus in accordance with characteristics of the printing material, and by performing the printing operation accordingly.
The above objects are accomplished by an image printing apparatus according to the present invention, including: a photosensitive section for forming a latent electrostatic image; a charging section for charging the photosensitive section; an exposing section for forming the latent electrostatic image of a certain pattern by projecting a laser beam onto the photosensitive section which is charged by the charging section, and by selectively eliminating the electric charge of the photosensitive section; a developing section for developing the latent electrostatic image by applying developer onto the latent electrostatic image formed on the photosensitive section; a transferring/fixing section for transferring the image developed by the developing section to a printing material; a printing material feeding section for sequentially supplying the printing material to the transferring/fixing section; a data reading section for reading printing material data recorded on the printing material which is fed by the printing material feeding section; and a controlling section for controlling the above components of the image printing apparatus, and for determining the printability of the printing material based on the data about the printing material which are read by the data reading section, and when the printing material is determined as acceptable, for setting functional set values for the respective components of the image printing apparatus in accordance with the characteristics of the printing material to output an optimum image.
Here, the data about the printing material are recorded in the form of a bar code, and the data reading section is formed of a reflective photo sensor for detecting the data about the printing material by projecting a laser beam onto the bar code and converting the reflected laser beam into electric pulse signals. The data about the printing material include both of data about maintenance such as the brand name, model name, manufacturer""s name, manufacturing date, durability, and term of use (expiration date), and data about the characteristics of the printing material such as the size, thickness, material type, surface roughness, glossiness, permittivity, and conductivity. Among these, the data displaying section selectively displays one of the model name, brand name, or the manufacturer""s name.
According to the preferred embodiment of the present invention, the photosensitive section is formed of a photosensitive belt wrapped around a plurality of belt rollers disposed within the body frame to travel a certain path, and further includes an antistatic section for eliminating residual electric charge on the photosensitive belt.
Further, the image printing apparatus according to the present invention further includes a data displaying section for displaying one of data about the printing material read by the data reading section, and more specifically, the data displaying section selectively displays one of the model name, brand name, or the manufacturer""s name.
Further, the image printing apparatus according to the present invention further includes an alarm section for letting the user know when the printing material is determined as unacceptable for printing by the controlling section, and a user input section for inputting commands from the user whether to proceed the printing ignoring the alarm of the alarm section, or cancel the printing, or print the image on another printing material.
Meanwhile, a controlling method for the image printing apparatus according to the present invention includes steps of: a) reading the data about the printing material which is fed; b) determining the printability of the printing material by the data about the printing material read from step a); and c) performing the printing process by resetting the functional set values for the components of the image printing apparatus in accordance with the characteristics of the printing material when determining the printing material as acceptable for printing, and temporally stopping the printing process when determining that the printing material is unacceptable for printing.
Here, the printability of the printing material is determined by comparing the data about the printing material read by the data reading section with standard data pre-stored in a memory of the image printing apparatus.
According to the preferred embodiment of the present invention, the controlling method of the image printing apparatus further includes a step for selectively displaying one of the model name, brand name, or the manufacturer""s name of the printing material which are read from step a).
Further, the controlling method of the image printing apparatus according to the present invention further includes step e) for selectively displaying one of the model name, brand name, or the manufacturer""s name, while simultaneously displaying an alarm or error message when the printing material is determined as being unacceptable for printing in step c).
When the alarm and error message are displayed, the user can select whether to proceed with the printing, or cancel the printing, or continue printing onto another printing material. Accordingly, upon receipt of the printing proceed command, printing is performed, ignoring the data about the printing material read by the data reading section, in accordance with the functional set values for the respective components of the image printing apparatus which are initially set, or, upon receipt of the printing cancel command, the image is not printed on the printing material, and the prepared printing data are erased, and the printing material is put out, or, upon receipt of printing command onto another printing material, new printing material is fed and the data about the newly fed printing material are read after the exit of the printing material which was initially fed.
Accordingly, while determining the printability of the printing material by reading the characteristics of the printing material, the image printing apparatus performs printing by resetting the functional set values for the respective parts thereof in accordance with the characteristics of the printing material, so that the optimum image adjusted in accordance with the characteristics of the printing material can be outputted.